Habits Survey: Sellafield Review, 2016
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Cefas contract report C6028 Radiological Habits Survey: Sellafield Review, 2016 2017 Environment Report RL 03/17 This page has been intentionally left blank Environment Report RL 03/17 Radiological Habits Survey: Sellafield Review, 2016 Review of shellfish and fish consumption, and intertidal occupancy C.J. Garrod and F.J. Clyne 2017 The work described in this report was carried out under contract to the Environment Agency, the Food Standards Agency and the Office for Nuclear Regulation. Cefas contract C6028 FSA Project FS131008 Cefas Document Control Radiological Habits Survey: Sellafield Review, 2016 Environment Agency, Food Standards Agency and Office for Nuclear Submitted to: Regulation Date submitted: 31/03/2017 Project Manager: Fiona Clyne Report compiled by: Chris Garrod Quality control by: Alastair Dewar Approved by & date: Kins Leonard 30/03/2017 Version: Final Version Control History Author Date Comment Version Sent to EA, FSA and Chris Garrod 30/01/2017 Draft 1 ONR for comments. All amendments Chris Garrod 31/03/2017 Final completed. This report should be cited as: Garrod, C.J. and Clyne, F.J., 2017. Radiological Habits Survey: Sellafield Review, 2016. RL 03/17. Cefas, Lowestoft A copy can be obtained by downloading from the Cefas website: www.cefas.co.uk © Crown copyright, 2017 Page 2 of 17 CONTENTS 1. INTRODUCTION ............................................................................................................................. 4 2. SURVEY AREA .............................................................................................................................. 5 Figure 1. The aquatic survey area .................................................................................................. 5 3. CONDUCT OF THE SURVEY ........................................................................................................ 6 4. METHODS OF DATA ANALYSIS .................................................................................................. 6 4.1 Data recording and presentation ............................................................................................. 6 Table A. Names of age groups and range of ages within each age group. .................................... 7 4.2 Approaches for the identification of high rates ........................................................................ 7 5. INTERNAL EXPOSURE ................................................................................................................. 8 5.1 Crustaceans, molluscs and fish .............................................................................................. 8 Table B. Summary of consumption rates of foods from the aquatic survey area ............................ 8 5.2 Composition of the food groups for crustaceans, molluscs and fish, for use in dose assessments, and comparison with 2015 data ....................................................................... 9 5.3 Consumption trends .............................................................................................................. 10 Figure 2. Consumption rates for the adult high-rate group for crustaceans, 2007 – 2016 (kg y-1) ....................................................................................................................................................... 11 Figure 3. Consumption rates for the adult high-rate group for molluscs, 2007 – 2016 (kg y-1) .... 11 6. EXTERNAL EXPOSURE .............................................................................................................. 12 6.1 Intertidal occupancy .............................................................................................................. 12 Table C. Summary of adults’ intertidal occupancy rates .............................................................. 12 Table D. Summary of adults’ intertidal occupancy rates from the 2015 Sellafield Review .......... 13 Figure 4. Comparison between the 2015 and 2016 mean rates of the high-rate groups for occupancy over each intertidal substrate ...................................................................................... 14 7. USE OF HABITS DATA FOR DOSE ASSESSMENTS .............................................................. 14 7.1 Aquatic combinations for adults in the Sellafield area .......................................................... 14 7.2 Habits data for source specific assessments ........................................................................ 15 7.3 Profiled habits data for total dose assessments ................................................................... 15 8. SUMMARY AND RECOMMENDED DATA FOR USE IN RIFE-22 DOSE ASSESSMENTS ...... 16 9. REFERENCES .............................................................................................................................. 17 TABLES Table 1 Adults' consumption rates of crustaceans from the Sellafield aquatic survey area (kg y-1) Table 2 Adults' consumption rates of molluscs from the Sellafield aquatic survey area (kg y-1) Table 3 Adult's consumption rates of fish from the Sellafield aquatic survey area (kg y-1) Table 4 Adults' intertidal occupancy rates in the Sellafield aquatic survey area (h y-1) Table 5 Aquatic combinations for adults in the Sellafield area ANNEXES Annex 1 Adults' consumption rates (kg y-1) and intertidal occupancy rates (h y-1) in the Sellafield area Annex 2a Sellafield Fishing Community consumption and intertidal occupancy data reported in AEMR and RIFE (kg y-1 and h y-1) Annex 2b Sellafield Fishing Community 5-year average consumption and intertidal occupancy rates (kg y-1 and h y-1) Annex 3 Summary of profiles for adults in the Sellafield area for use in the assessment of total dose Page 3 of 17 1. INTRODUCTION This report describes a review of the public’s shellfish and fish consumption, and intertidal occupancy, relating to liquid radioactive waste discharges from the Sellafield Ltd nuclear site in Cumbria. It is also relevant to discharges from the Low Level Waste Repository (LLWR) near Drigg due to the proximity of the site, as well as the proposed Moorside nuclear power station adjacent to the Sellafield site. The information and data in this report are used in radiological dose assessments as reported in the Radioactivity in Food and the Environment (RIFE) series (e.g. EA, FSA, FSS, NRW, NIEA and SEPA, 2016). The study was funded by the Environment Agency (EA), the Food Standards Agency (FSA) and the Office for Nuclear Regulation (ONR) to support their roles in protecting the public from the effects of radiation. Radiological protection of the public is based on the concept of a ‘representative person’. This notional individual is defined as being representative of the more highly exposed members of the population. It follows that, if the dose to the representative person is acceptable when compared to dose limits and optimisation, then other members of the public will receive acceptable doses, and overall protection to the public is provided from the effects of radiation. This Sellafield Review specifically investigated the consumption of crustaceans, molluscs and fish, and occupancy over intertidal substrates, since these pathways are the major contributors to the dose of the representative person. Reviews are conducted annually, except in years when full surveys are undertaken, because consumption and occupancy rates have been known to vary from year to year, with some people ceasing seafood consumption, shellfish collection or intertidal activities, and new individuals being identified. The last full habits survey (encompassing aquatic, terrestrial and direct radiation pathways) in the vicinity of Sellafield was conducted by the Centre for Environment, Fisheries & Aquaculture Science (Cefas) in 2013 (Clyne et al., 2014). The consumption of fish has historically not been targeted for the Sellafield Reviews because fish have generally been of lower radiological significance around Sellafield than shellfish and intertidal occupancy. However, the people interviewed in relation to shellfish consumption and intertidal occupancy have been asked about their fish consumption. Prior to 2015, these fish consumption rates were used to update the total dose assessment of additive exposure but the fish consumption rates from the most recent full Sellafield habits surveys were used for the Sellafield source specific aquatic dose assessments. More recently, the relative contribution to doses arising from fish consumption has increased, and therefore, since 2015, a mean rate for the high-rate group for fish has been presented in these annual Sellafield Reviews, which can be used in the Sellafield source specific aquatic dose assessments. The fish consumption rates will also be used to update the total dose assessment. The adequacy of the inclusion of the mean rate for the high-rate group for fish in the Sellafield source specific aquatic dose assessments using the consumption rates from the Sellafield Review will be reviewed in future years. Page 4 of 17 Handling rates of sediment and fishing gear are not obtained during Sellafield Reviews, therefore, for assessments purposes, the mean handling rates for the high-rate groups for fishing gear and sediment will be retained from the 2013 full Sellafield habits survey. In addition to the habits surveys undertaken in the vicinity of Sellafield, several of the higher rate consumers of shellfish keep a diary of their seafood consumption and intertidal occupancy for a two- week period every three months. These